Internal pipe bender



y 4, 1968 J. H. ANDERSON 3,382,698

INTERNAL PIPE BENDER Filed March 9, 1966 2 Sheets-Sheet 1 FIG. I

f r 24 20 38 38 7e HQ 2 INVENTOR J. HILBERT ANDERSON ATTORNEYS,

May 14, 1968 J. H. ANDERSON INTERNAL PIPE B'ENDER 2 Sheets-Sheet 2 Filed March 9, 1966 FIG. 3

FIG. 4

I30 I26 I 4/ INVENTOR HILBERT ANDERSON ATTORNEYS.

United States Patent Ofl ice sssaess Patented May 14, 1968 3,382,698 INTERNAL PIPE BENDER James H. Anderson, 1615 Hilloek Lane, York, Pa. 17403 Filed Mar. 9, 1966, Ser. No. 532,903 7 Claims. (Cl. 72-498) This invention relates broadly to devices for the bending of pipe and more specifically to improvements in an internal pipe bending apparatus.

The present invention embraces certain of the general principles as set forth in my co-pending application Ser. No. 359,902, now Patent No. 3,274,817, filed Apr. 15, 1964, and is regarded as constituting an improvement upon said application.

The pipe bending apparatus of the present invention is directed to the use of a plurality of annular members which have piston and cylinder assemblies or units connected thereto and whereby said units may be actuated either hydraulically or pneumatically. The piston and cylinder of each assembly or unit are both connected to spaced annular members that are positioned within a pipe with the two outermost annular members having but a single point of connection while the inner annular member is provided with an upper and lower point of connection for said piston and cylinder units. Such an arrangement permits the bending of a pipe, upon the actuation of the several piston-cylinder units, in such a manner that the pipe is free of Wrinkles in the area of the bend. This is due, in a great degree, to the use of a plurality of piston and cylinder assemblies or units wherein the pressure of the fluid can be readily controlled with respect to each unit and in turn the forces being exerted upon the pipe may be controlled in a rather precise manner to produce the desired bending effect.

One of the objects of the present invention is to provide a pipe bender having a plurality of spaced annular members engaging the inner surface of a pipe with means connected to and carried by said members for moving same to effect a bending of the pipe.

Another object is to provide a pipe bender having a plurality of spaced annular members engageable with the inner surface of a pipe and a plurality of piston-cylinder assemblies connected to said annular members for moving said annular members in different directions to etfect a bending of the pipe.

A further object is to provide three spaced annular members engaging the inner surface of a pipe with hydraulically actuated piston and cylinder units connected to said members for moving the central member in a direction opposite to the direction of movement of the two outer members for bending the pipe.

Other objects are to provide a pipe bender which is susceptible of easy operation, which leaves the pipe wrinkle and bulge free and which is economical of manufacture.

Other objects and advantages, more or less ancillary to the foregoing in the manner in which all of the various objects are realized, will appear in the following description, which, when considered in connection with the accompanying drawings, sets forth the preferred embodiment of the invention.

Referring to the drawings wherein the preferred embodiment of the invention is illustrated:

FIGURE 1 is an elevational view in section of a pipe bending apparatus embodying the present invention;

FIGURE 2 is an elevational view in section of the pipe bending apparatus of FIGURE 1 showing the position of the various parts at the termination of a bending operation;

FIGURE 3 is a vertical sectional view of a portion of the apparatus of FIGURE 1, the view being taken along the line 3-3 of FIGURE 1; and

FIGURE 4 is an elevational view in section of a modified pipe bending apparatus embodying the features of the present invention.

Referring to FIGURE 1, there is shown a section of pipe 10 within which are positioned a pair of annular gripping members 12 and 14 arranged in spaced relation to one another. The pipe 10 has also positioned therein intermediate the gripping members 12 and 14 a ring or annular member 16 whose external diameter is .slightly less than the internal diameter of the pipe 10. The ring 16 has detachably mounted thereon an annular sleeve or shoe 18 which is preferably formed with a slightly sperical or convex outer surface for engaging the inner surface of the pipe 10. The sleeve or shoe 18 may be formed of a material which is softer than the material of the pipe so as to avoid scratching or marring the inner surface of the pipe during the bending operation. The use of a detachable sleeve or shoe 18 in conjunction with the ring 16 not only permits the ready replacement of said shoe or sleeve due to wear thereof, but enables the ring 16 to be used with sleeves or shoes of different thickness dependent upon the bore or internal diameter of the pipe 10. Furthermore, by providing the sleeve or shoe 1% with a spherical or convex outer surface, the ring and shoe will tend to conform to the contour of the pipe during the bending operation and to a certain degree aid in abetting said bending without causing wrinkles to be formed in the surface of the pipe and at the same time, insuring that the inner surface of the pipe will remain free from scratches and the like.

The gripping members 12 and 14 are identical with one another in all respects so that the following description Will be directed to just one of said members. The gripping member 12 is formed with a peripheral annular chamber 26 which has an open end for the reception of an expansible sealing ring 22. The sealing ring 22 is preferably formed of an elastomeric material and has its edges 24 bent or turned inwardly for slidably engaging the outer end portions of the gripping member 12 that define the chamber 20 for the purpose of sealing the open end of said chamber. The sealing ring 22 has positioned thereon an annular split ring 26, which is preferably formed of a relatively hard material, such as steel or the like, and provides an expansible backing member for said sealing ring. The ring 26 is formed with a plurality of spaced slots 28, FIGURE 3, which permit said ring to hex to a certain degree. The ring 26 is also provided on its outer surface with a groove or recess for the reception of an annular shoe or member 39 which is formed from a material that is harder than the material from which the pipe to be bent is formed. The annular shoe or member 30 is also formed with a plurality of spaced slots 32, which enable said member to be expanded into engagement with the inner surface of the pipe 10. The chamber 20 has connected thereto a flexible conduit 34 which is in communication with a source of hydraulic pressure, not shown, for the purpose of alternately supplying and bleeding hydraulic fiuid to and from said chamber and thus, permitting said sealin ring 2-2 to move radially inwardly or outwardly of said chamber and thus, move ring 26 and member 30.

The gripping members 12 and 14 are each provided with a centrally disposed trunnion member 36 to which is secured one end of a pair of connecting rods 38 and 40. The other or free end of the rods 38 are aflixed to cylinders 42, which have positioned therein pistons 44. The pistons 44 are provided with conventional piston rods 46 which are connected to a trunnion 48 that is mounted in the ring 16 above the center line of said ring. The cylinders 42 have afiixed to the lower or open end thereof a closure plate 56 that is provided with a central aperture through which the piston rod 46 extends. The apertures in the closure plates 56- have suitable sealing means, such as rings 52, mounted therein which provide effective seals for the piston rods 46 While still permitting said rods to have a reciprocatory movement with respect to the closure plate 50.

The connecting rods 49 likewise have their other or free ends secured to a cylinder 54 within which is positioned a piston 56 that has a piston rod 58 which is connected to a trunnion 60 Which is mounted in the ring 16 below the center line thereof. Thus, the trunnions 48 and 60 to which the piston rods 46 and 64 are connected are arranged as chordal members in spaced parallel relation to one another within the ring 16. The cylinders 54 are also provided with closure plates 62 which have suitable apertures therein and O ring sealing members 64 to provide effective seals for the piston rods 58. As a result of closing the ends of the cylinders 42 and 54 with plates 56 and 62, the pistons 44 and 56 operate between a pair of pressure chambers 66 and 68. Each of the chambers 66 have a pressure conduit 70 connected thereto while each of the chambers 68 have a pressure conduit 72 connected thereto, which conduits are in turn connected to a suitable source of pressure, not shown.

In operation, the apparatus is positioned within a pipe 16 in the area Where the pipe is to be bent and fluid under pressure is delivered to the chamber 20 by means of the conduit 34 so as to radially expand the sealing ring 22 and shoe member 30. The gripping members 12 and 14 as well as ring 16 are positioned as a unit within the pipe and the trunnions 36, 4S and 60 are positioned in a plane normal to the longitudinal axis of the pipe. The pressure of the fluid in the chamber 20 is retained at a point sufiicient to insure the anchoring or retention of the gripping member 12 in engagement with the inner surface of the pipe 10. The cylinders 42 and pistons 44 as well as cylinders 54 and pistons 56 are then shortened by introducing fluid into the chambers 68 by way of the conduits 72 so as to move the pistons away from the closure plates 50 and 62 and towards the ends of the cylinders. This action causes ring 16 and gripping member 14 to be drawn towards gripping member 12. This movement of the ring 16 and gripping member 14 is continued to a point where they are properly positioned within the pipe for effecting the bending thereof in the desired area. Upon the positioning of the ring 16 and gripping member 14 within the pipe fluid is introduced into the chamber 20 in the gripping member 14 by way of conduit 34 so as to expand the sealing ring 22 radially outward and move the shoe member into gripping engagement with the inner surface of the pipe 10. This positioning and anchorin of the ring 16 and gripping member 14 is in effect carried by the pistons 44 and 56 being moved towards the end of the cylinders 42 and 54.

The gripping members 12 and 14 having been firmly anchored within the pipe 16, the cylinder and piston as semblies 42 and 44 are then placed in compression. by introducing into chambers 66 by way of conduits 70 hydraulic fluid under pressure while at the same time, the cylinder and piston assemblies 54 and 56 are being retained in tension. This combination of forces acting upon the trunnions 4-8 and 60 results in ring 16 being pushed upwardly while gripping members 12 and 14 are being pushed downwardly or downwardly and outwardly in a direction opposite to the direction of movement of the ring 16. It is to be noted in the positioning of the ring 16 and gripping member 14 with respect to gripping member 12 that the movement of the pistons 56 within the cylinders 44 was such that the pistons were not bottomed but were moved to a point where they were spaced from the ends of the cylinders. Thus, during the period 4 When the cylinder and piston assemblies 42 and 44 were being placed in compression, the pistons 56 were still capable of having a slight additional movement within the cylinders 54, which additional movement resulted in a further contraction of the piston and cylinder assembly thereby aiding in pushing the ring 16 in one direction While moving the gripping members 12 and 14 in the opposite direction to eifect a bending of the pipe 10.

Inasmuch as the pressure of the fluid delivered through the conduits 7t) and 72 can be readily controlled, the resultant forces imparted to the ring 16 by means of the cylinder and piston assemblies can also be controlled to give the desired bending effect. Thus, it very readily may be that the forces imparted in the cylinder piston assemblies 42 and 44 should be higher than the forces imparted in the piston-cylinder assemblies 54 and 56 and in this manner, the stresses in the pipe 16 would be higher in tension than in compression and thus, prevent a buckling of the pipe wall in the compression portion or area of the bend of the pipe. It is to be noted that through the present arrangement of gripping members and rings the axial forces on the gripping members 12 and 14 are relatively low during the bending operation due, undoubtedly, to the fact that the axial components of the cylinder and piston assemblies 42 and 44 oppose those of the cylinder and piston assemblies 54 and 56 so that one tends to cancel out the other.

In FIGURE 1, there is shown connected to the gripping member 12 adjacent the chamber 20 a pipe 74 that terminates in a spray nozzle 76. The pipe 74 is connected to a flexible conduit, not shown, for delivering to the nozzle 76 a liquid that could be directed upon the inner surface. The liquid that is directed upon the pipe could contain a Wetting agent to increase the friction for the gripping members 12 or it might contain a quick setting cement to secure the gripping member 12 to the inner surface of the pipe. If a cement were sprayed upon the inner surface of the pipe 11 a solvent and lubricating agent could then be sprayed upon the pipe interior after the bending operation to effect a release of the gripping member 12. While only a single nozzle 76 has been shown, it is to be understood that a plurality of said nozzles could be secured to the gripping member 12 and the same could also apply to the ring 16 and gripping member 14.

In the modified form of the invention shown in FIG- URE 4, the same general arrangement of parts is to be found with respect to the gripping members and intermediate ring and said parts have been identified with the same reference numeral only in the next higher series. It is to be noted that the cylinder and piston assemblies 142 and 144 are of the same size as the cylinder and piston assemblies shown in FIGURES 1 and 2 and said cylinder and piston assemblies are also connected to the upper trunnion or chordal member 148 and positioned between the ring 116 and gripping members 112 and 114. The cylinder and piston assemblies 154 and 156 are of a larger size than the cylinder and piston assemblies 54 and 56, shown in FIGURES 1 and 2, and by locating the cylinder and piston assemblies 154 and 156 outwardly of the gripping members 112 and 114 instead of positioning them between said gripping members and the ring member 116, said cylinder and piston assemblies 154 and 156 may be larger, which arrangement might be found advisable under certain conditions. However, the mode of operation of the cylinder and piston assemblies shown in FIGURE 4 is identical with that as embodied in FIGURES 1 and 2 so that the ring 116 is moved in one direction while the gripping members 112 and 114 are moved in the opposite direction to efiect a bending of the pipe.

Although the foregoing description is necessarily of a detailed character, in order that the invention may be completely set forth, it is to be understood that the specific terminology is not intended to be restrictive or confining and that various rearrangements of parts and modi- 5 fications of detail may be resorted to Without departing from the scope or spirit as herein claimed.

I claim:

1. An apparatus for bending a tubular structure comprising gripping members positioned within a tubular structure in axially spaced relation to one another, means to actuate at least one of said gripping members for engaging said tubular structure, an annular member positioned within said tubular structure intermediate said gripping members, said gripping members each having a centrally positioned transverse member mounted therein, said annular member having a pair of chordal members positioned therein in spaced parallel relation to one another, and means interposed between said annular member and each of said gripping members for displacing said annular member with respect to said gripping members and effecting a bend in said tubular structure.

2. An apparatus as set forth in claim 1 wherein said last mentioned means initially effects a movement in said tubular structure of said annular member and a gripping member with respect to the gripping member in engagement with said tubular structure.

3. An apparatus as set forth in claim 1 wherein said last mentioned means are connected to said chordal members and said transverse members.

4. An apparatus as set forth in claim 1 wherein said annular member is provided with a detachable annular shoe having a curved outer surface for engaging the tubular structure.

5. An apparatus as set forth in claim 1 wherein said last mentioned means includes cylinder and piston assemblies connected to said chordal members and said transverse members.

6. An apparatus as set forth in claim 5 wherein said pistons are connected to said chordal members and said cylinders are connected to said transverse members.

7. An apparatus as set forth in claim 5 wherein one of said chordal members is connected to a plurality of cylinders and the other chordal member is connected to a plurality of pistons with said transverse members connected to both piston and cylinders.

References Cited UNITED STATES PATENTS 520,870 6/ 1894 Winfield 72-298 606,785 7/ 1898 Kemp 72-295 678,946 7/ 1901 Dieckmann 72-311 1,804,384 5/1931 Miller 72-298 2,371,393 3/1945 Horrigan 72-392 3,109,477 11/1963 Avera 72-466 3,274,817 9/1966 Anderson 72-298 RICHARD J. HERBST, Primary Examiner.

K. C. DECKER, Assistant Examiner. 

1. AN APPARATUS FOR BENDING A TUBULAR STRUCTURE COMPRISING GRIPPING MEMBERS POSITIONED WITHIN A TUBULAR STRUCTURE IN AXIALLY SPACED RELATION TO ONE ANOTHER, MEANS TO ACTUATE AT LEAST ONE OF SAID GRIPPING MEMBERS FOR ENGAGING SAID TUBULAR STRUCTURE, AN ANNULAR MEMBER POSITIONED WITHIN SAID TUBULAR STRUCTURE INTERMEDIATE SAID GRIPPING MEMBERS, SAID GRIPPING MEMBERS EACH HAVING A CENTRALLY POSITIONED TRANSVERSE MEMBER MOUNTED THEREIN, 